New York Police Department Photographs, 1915-1940s. WARNING: THIS COLLECTION CONTAINS GRAPHIC IMAGES OF HOMICIDE VICTIMS. In addition to crime-scene and law-enforcement photographs, this collection includes photographs from the departmental operations and emergency services units, dating from 1928 to 1941. The departmental photographs document activities unrelated to criminal investigations such as political organizations monitored by the "Alien Squad." The Emergency Services Unit photographs document mayhem including street car accidents, early airplane crashes, explosions, drowning victims, and the proverbial cat stuck in a tree. Crime-scene photographs depict homicide victims, police officers, vehicles, horses, dogs, evidence, police equipment, mug shots, and fingerprints. For the homicide pictures, the police used special tripods with the camera suspended above the victim. The collection also includes images accessioned from the New York and Brooklyn District Attorneys.